package com.stanfy.io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FilterInputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;


/**
 * <p>Encodes and decodes to and from Base64 notation.</p>
 * <p>Homepage: <a href="http://iharder.net/base64">http://iharder.net/base64</a>.</p>
 *
 * <p>Example:</p>
 *
 * <code>String encoded = Base64.encode(myByteArray);</code>
 * <br />
 * <code>byte[] myByteArray = Base64.decode(encoded);</code>
 *
 * <p>The <tt>options</tt> parameter, which appears in a few places, is used to pass
 * several pieces of information to the encoder. In the "higher level" methods such as
 * encodeBytes(bytes, options) the options parameter can be used to indicate such
 * things as first gzipping the bytes before encoding them, not inserting linefeeds,
 * and encoding using the URL-safe and Ordered dialects.</p>
 *
 * <p>Note, according to <a href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548</a>,
 * Section 2.1, implementations should not add line feeds unless explicitly told
 * to do so. I've got Base64 set to this behavior now, although earlier versions
 * broke lines by default.</p>
 *
 * <p>The constants defined in Base64 can be OR-ed together to combine options, so you
 * might make a call like this:</p>
 *
 * <code>String encoded = Base64.encodeBytes(mybytes, Base64.GZIP | Base64.DO_BREAK_LINES);</code>
 * <p>to compress the data before encoding it and then making the output have newline characters.</p>
 * <p>Also...</p>
 * <code>String encoded = Base64.encodeBytes(crazyString.getBytes());</code>
 *
 *
 *
 * <p>
 * Change Log:
 * </p>
 * <ul>
 *  <li>v2.3.7 - Fixed subtle bug when base 64 input stream contained the
 *   value 01111111, which is an invalid base 64 character but should not
 *   throw an ArrayIndexOutOfBoundsException either. Led to discovery of
 *   mishandling (or potential for better handling) of other bad input
 *   characters. You should now get an IOException if you try decoding
 *   something that has bad characters in it.</li>
 *  <li>v2.3.6 - Fixed bug when breaking lines and the final byte of the encoded
 *   string ended in the last column; the buffer was not properly shrunk and
 *   contained an extra (null) byte that made it into the string.</li>
 *  <li>v2.3.5 - Fixed bug in {@link #encodeFromFile} where estimated buffer size
 *   was wrong for files of size 31, 34, and 37 bytes.</li>
 *  <li>v2.3.4 - Fixed bug when working with gzipped streams whereby flushing
 *   the Base64.OutputStream closed the Base64 encoding (by padding with equals
 *   signs) too soon. Also added an option to suppress the automatic decoding
 *   of gzipped streams. Also added experimental support for specifying a
 *   class loader when using the
 *   {@link #decodeToObject(java.lang.String, int, java.lang.ClassLoader)}
 *   method.</li>
 *  <li>v2.3.3 - Changed default char encoding to US-ASCII which reduces the internal Java
 *   footprint with its CharEncoders and so forth. Fixed some javadocs that were
 *   inconsistent. Removed imports and specified things like IOException
 *   explicitly inline.</li>
 *  <li>v2.3.2 - Reduced memory footprint! Finally refined the "guessing" of how big the
 *   final encoded data will be so that the code doesn't have to create two output
 *   arrays: an oversized initial one and then a final, exact-sized one. Big win
 *   when using the {@link #encodeBytesToBytes(byte[])} family of methods (and not
 *   using the gzip options which uses a different mechanism with streams and stuff).</li>
 *  <li>v2.3.1 - Added {@link #encodeBytesToBytes(byte[], int, int, int)} and some
 *   similar helper methods to be more efficient with memory by not returning a
 *   String but just a byte array.</li>
 *  <li>v2.3 - <strong>This is not a drop-in replacement!</strong> This is two years of comments
 *   and bug fixes queued up and finally executed. Thanks to everyone who sent
 *   me stuff, and I'm sorry I wasn't able to distribute your fixes to everyone else.
 *   Much bad coding was cleaned up including throwing exceptions where necessary
 *   instead of returning null values or something similar. Here are some changes
 *   that may affect you:
 *   <ul>
 *    <li><em>Does not break lines, by default.</em> This is to keep in compliance with
 *      <a href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548</a>.</li>
 *    <li><em>Throws exceptions instead of returning null values.</em> Because some operations
 *      (especially those that may permit the GZIP option) use IO streams, there
 *      is a possiblity of an IOException being thrown. After some discussion and
 *      thought, I've changed the behavior of the methods to throw IOExceptions
 *      rather than return null if ever there's an error. I think this is more
 *      appropriate, though it will require some changes to your code. Sorry,
 *      it should have been done this way to begin with.</li>
 *    <li><em>Removed all references to System.out, System.err, and the like.</em>
 *      Shame on me. All I can say is sorry they were ever there.</li>
 *    <li><em>Throws NullPointerExceptions and IllegalArgumentExceptions</em> as needed
 *      such as when passed arrays are null or offsets are invalid.</li>
 *    <li>Cleaned up as much javadoc as I could to avoid any javadoc warnings.
 *      This was especially annoying before for people who were thorough in their
 *      own projects and then had gobs of javadoc warnings on this file.</li>
 *   </ul>
 *  <li>v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug
 *   when using very small files (~&lt; 40 bytes).</li>
 *  <li>v2.2 - Added some helper methods for encoding/decoding directly from
 *   one file to the next. Also added a main() method to support command line
 *   encoding/decoding from one file to the next. Also added these Base64 dialects:
 *   <ol>
 *   <li>The default is RFC3548 format.</li>
 *   <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates
 *   URL and file name friendly format as described in Section 4 of RFC3548.
 *   http://www.faqs.org/rfcs/rfc3548.html</li>
 *   <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates
 *   URL and file name friendly format that preserves lexical ordering as described
 *   in http://www.faqs.org/qa/rfcc-1940.html</li>
 *   </ol>
 *   Special thanks to Jim Kellerman at <a href="http://www.powerset.com/">http://www.powerset.com/</a>
 *   for contributing the new Base64 dialects.
 *  </li>
 *
 *  <li>v2.1 - Cleaned up javadoc comments and unused variables and methods. Added
 *   some convenience methods for reading and writing to and from files.</li>
 *  <li>v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems
 *   with other encodings (like EBCDIC).</li>
 *  <li>v2.0.1 - Fixed an error when decoding a single byte, that is, when the
 *   encoded data was a single byte.</li>
 *  <li>v2.0 - I got rid of methods that used booleans to set options.
 *   Now everything is more consolidated and cleaner. The code now detects
 *   when data that's being decoded is gzip-compressed and will decompress it
 *   automatically. Generally things are cleaner. You'll probably have to
 *   change some method calls that you were making to support the new
 *   options format (<tt>int</tt>s that you "OR" together).</li>
 *  <li>v1.5.1 - Fixed bug when decompressing and decoding to a
 *   byte[] using <tt>decode(String s, boolean gzipCompressed)</tt>.
 *   Added the ability to "suspend" encoding in the Output Stream so
 *   you can turn on and off the encoding if you need to embed base64
 *   data in an otherwise "normal" stream (like an XML file).</li>
 *  <li>v1.5 - Output stream pases on flush() command but doesn't do anything itself.
 *      This helps when using GZIP streams.
 *      Added the ability to GZip-compress objects before encoding them.</li>
 *  <li>v1.4 - Added helper methods to read/write files.</li>
 *  <li>v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.</li>
 *  <li>v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream
 *      where last buffer being read, if not completely full, was not returned.</li>
 *  <li>v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.</li>
 *  <li>v1.3.3 - Fixed I/O streams which were totally messed up.</li>
 * </ul>
 *
 * <p>
 * I am placing this code in the Public Domain. Do with it as you will.
 * This software comes with no guarantees or warranties but with
 * plenty of well-wishing instead!
 * Please visit <a href="http://iharder.net/base64">http://iharder.net/base64</a>
 * periodically to check for updates or to contribute improvements.
 * </p>
 *
 * @author Robert Harder
 * @author rob@iharder.net
 * @version 2.3.7
 */
public final class Base64 {

  /* ********  P U B L I C   F I E L D S  ******** */


  /** No options specified. Value is zero. */
  public static final int NO_OPTIONS = 0;

  /** Specify encoding in first bit. Value is one. */
  public static final int ENCODE = 1;


  /** Specify decoding in first bit. Value is zero. */
  public static final int DECODE = 0;


  /** Specify that data should be gzip-compressed in second bit. Value is two. */
  public static final int GZIP = 2;

  /** Specify that gzipped data should <em>not</em> be automatically gunzipped. */
  public static final int DONT_GUNZIP = 4;


  /** Do break lines when encoding. Value is 8. */
  public static final int DO_BREAK_LINES = 8;

  /**
   * Encode using Base64-like encoding that is URL- and Filename-safe as described
   * in Section 4 of RFC3548:
   * <a href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>.
   * It is important to note that data encoded this way is <em>not</em> officially valid Base64,
   * or at the very least should not be called Base64 without also specifying that is
   * was encoded using the URL- and Filename-safe dialect.
   */
  public static final int URL_SAFE = 16;


  /**
   * Encode using the special "ordered" dialect of Base64 described here:
   * <a href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
   */
  public static final int ORDERED = 32;


  /* ********  P R I V A T E   F I E L D S  ******** */


  /** Maximum line length (76) of Base64 output. */
  private static final int MAX_LINE_LENGTH = 76;


  /** The equals sign (=) as a byte. */
  private static final byte EQUALS_SIGN = (byte)'=';


  /** The new line character (\n) as a byte. */
  private static final byte NEW_LINE = (byte)'\n';


  /** Preferred encoding. */
  private static final String PREFERRED_ENCODING = "US-ASCII";

  /** Indicates white space in encoding. */
  private static final byte WHITE_SPACE_ENC = -5;
  /** Indicates equals sign in encoding. */
  private static final byte EQUALS_SIGN_ENC = -1;

  /** Mask value. */
  private static final int MASK_0XFF = 0xFF, MASK_0XFF00 = 0xFF00;

  /* ********  S T A N D A R D   B A S E 6 4   A L P H A B E T  ******** */

  /** The 64 valid Base64 values. Host platform me be something funny like EBCDIC, so we hardcode these values. */
  private static final byte[] STANDARD_ALPHABET = {
    (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
    (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
    (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
    (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
    (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
    (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
    (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
    (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z',
    (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5',
    (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'+', (byte)'/'
  };


  /**
   * Translates a Base64 value to either its 6-bit reconstruction value
   * or a negative number indicating some other meaning.
   **/
  private static final byte[] STANDARD_DECODABET = {
    -9, -9, -9, -9, -9, -9, -9, -9, -9,                 // Decimal  0 -  8
    -5, -5,                                             // Whitespace: Tab and Linefeed
    -9, -9,                                             // Decimal 11 - 12
    -5,                                                 // Whitespace: Carriage Return
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
    -9, -9, -9, -9, -9,                                 // Decimal 27 - 31
    -5,                                                 // Whitespace: Space
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,             // Decimal 33 - 42
    62,                                                 // Plus sign at decimal 43
    -9, -9, -9,                                         // Decimal 44 - 46
    63,                                                 // Slash at decimal 47
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61,             // Numbers zero through nine
    -9, -9, -9,                                         // Decimal 58 - 60
    -1,                                                 // Equals sign at decimal 61
    -9, -9, -9,                                         // Decimal 62 - 64
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,       // Letters 'A' through 'N'
    14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,     // Letters 'O' through 'Z'
    -9, -9, -9, -9, -9, -9,                             // Decimal 91 - 96
    26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
    39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
    -9, -9, -9, -9, -9                                  // Decimal 123 - 127
    , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,   // Decimal 128 - 139
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9      // Decimal 244 - 255
  };


  /* ********  U R L   S A F E   B A S E 6 4   A L P H A B E T  ******** */

  /**
   * Used in the URL- and Filename-safe dialect described in Section 4 of RFC3548:
   * <a href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>.
   * Notice that the last two bytes become "hyphen" and "underscore" instead of "plus" and "slash."
   */
  private static final byte[] URL_SAFE_ALPHABET = {
    (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
    (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
    (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
    (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
    (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
    (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
    (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
    (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z',
    (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5',
    (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'-', (byte)'_'
  };

  /**
   * Used in decoding URL- and Filename-safe dialects of Base64.
   */
  private static final byte[] URL_SAFE_DECODABET = {
    -9, -9, -9, -9, -9, -9, -9, -9, -9,                 // Decimal  0 -  8
    -5, -5,                                      // Whitespace: Tab and Linefeed
    -9, -9,                                      // Decimal 11 - 12
    -5,                                         // Whitespace: Carriage Return
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 14 - 26
    -9, -9, -9, -9, -9,                             // Decimal 27 - 31
    -5,                                         // Whitespace: Space
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,              // Decimal 33 - 42
    -9,                                         // Plus sign at decimal 43
    -9,                                         // Decimal 44
    62,                                         // Minus sign at decimal 45
    -9,                                         // Decimal 46
    -9,                                         // Slash at decimal 47
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61,              // Numbers zero through nine
    -9, -9, -9,                                   // Decimal 58 - 60
    -1,                                         // Equals sign at decimal 61
    -9, -9, -9,                                   // Decimal 62 - 64
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,            // Letters 'A' through 'N'
    14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,        // Letters 'O' through 'Z'
    -9, -9, -9, -9,                                // Decimal 91 - 94
    63,                                         // Underscore at decimal 95
    -9,                                         // Decimal 96
    26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,     // Letters 'a' through 'm'
    39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,     // Letters 'n' through 'z'
    -9, -9, -9, -9, -9                              // Decimal 123 - 127
    , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 128 - 139
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 140 - 152
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 153 - 165
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 166 - 178
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 179 - 191
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 192 - 204
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 205 - 217
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 218 - 230
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 231 - 243
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9         // Decimal 244 - 255
  };



  /* ********  O R D E R E D   B A S E 6 4   A L P H A B E T  ******** */

  /**
   * I don't get the point of this technique, but someone requested it,
   * and it is described here:
   * <a href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
   */
  private static final byte[] ORDERED_ALPHABET = {
    (byte)'-',
    (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4',
    (byte)'5', (byte)'6', (byte)'7', (byte)'8', (byte)'9',
    (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
    (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
    (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
    (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
    (byte)'_',
    (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
    (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
    (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
    (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z'
  };

  /**
   * Used in decoding the "ordered" dialect of Base64.
   */
  private static final byte[] ORDERED_DECODABET = {
    -9, -9, -9, -9, -9, -9, -9, -9, -9,                 // Decimal  0 -  8
    -5, -5,                                      // Whitespace: Tab and Linefeed
    -9, -9,                                      // Decimal 11 - 12
    -5,                                         // Whitespace: Carriage Return
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 14 - 26
    -9, -9, -9, -9, -9,                             // Decimal 27 - 31
    -5,                                         // Whitespace: Space
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,              // Decimal 33 - 42
    -9,                                         // Plus sign at decimal 43
    -9,                                         // Decimal 44
    0,                                          // Minus sign at decimal 45
    -9,                                         // Decimal 46
    -9,                                         // Slash at decimal 47
    1, 2, 3, 4 , 5, 6, 7, 8, 9, 10,                       // Numbers zero through nine
    -9, -9, -9,                                   // Decimal 58 - 60
    -1,                                         // Equals sign at decimal 61
    -9, -9, -9,                                   // Decimal 62 - 64
    11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,     // Letters 'A' through 'M'
    24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,     // Letters 'N' through 'Z'
    -9, -9, -9, -9,                                // Decimal 91 - 94
    37,                                         // Underscore at decimal 95
    -9,                                         // Decimal 96
    38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,     // Letters 'a' through 'm'
    51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,     // Letters 'n' through 'z'
    -9, -9, -9, -9, -9                                 // Decimal 123 - 127
    , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 128 - 139
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 140 - 152
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 153 - 165
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 166 - 178
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 179 - 191
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 192 - 204
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 205 - 217
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 218 - 230
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9,     // Decimal 231 - 243
    -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9         // Decimal 244 - 255
  };


  /** Defeats instantiation. */
  private Base64() { }


  /* ********  D E T E R M I N E   W H I C H   A L H A B E T  ******** */


  /**
   * Returns one of the _SOMETHING_ALPHABET byte arrays depending on
   * the options specified.
   * It's possible, though silly, to specify ORDERED <b>and</b> URLSAFE
   * in which case one of them will be picked, though there is
   * no guarantee as to which one will be picked.
   */
  private static byte[] getAlphabet(final int options) {
    if ((options & URL_SAFE) == URL_SAFE) {
      return URL_SAFE_ALPHABET;
    } else if ((options & ORDERED) == ORDERED) {
      return ORDERED_ALPHABET;
    } else {
      return STANDARD_ALPHABET;
    }
  } // end getAlphabet


  /**
   * Returns one of the _SOMETHING_DECODABET byte arrays depending on
   * the options specified.
   * It's possible, though silly, to specify ORDERED and URL_SAFE
   * in which case one of them will be picked, though there is
   * no guarantee as to which one will be picked.
   */
  private static byte[] getDecodabet(final int options) {
    if ((options & URL_SAFE) == URL_SAFE) {
      return URL_SAFE_DECODABET;
    } else if ((options & ORDERED) == ORDERED) {
      return ORDERED_DECODABET;
    } else {
      return STANDARD_DECODABET;
    }
  } // end getAlphabet




  /* ********  E N C O D I N G   M E T H O D S  ******** */


  /**
   * Encodes up to the first three bytes of array <code>threeBytes</code>
   * and returns a four-byte array in Base64 notation.
   * The actual number of significant bytes in your array is
   * given by <code>numSigBytes</code>.
   * The array <code>threeBytes</code> needs only be as big as
   * <code>numSigBytes</code>.
   * Code can reuse a byte array by passing a four-byte array as <code>b4</code>.
   *
   * @param b4 A reusable byte array to reduce array instantiation
   * @param threeBytes the array to convert
   * @param numSigBytes the number of significant bytes in your array
   * @return four byte array in Base64 notation.
   * @since 1.5.1
   */
  private static byte[] encode3to4(final byte[] b4, final byte[] threeBytes, final int numSigBytes, final int options) {
    encode3to4(threeBytes, 0, numSigBytes, b4, 0, options);
    return b4;
  }   // end encode3to4


  /**
   * <p>Encodes up to three bytes of the array <code>source</code>
   * and writes the resulting four Base64 bytes to <code>destination</code>.
   * The source and destination arrays can be manipulated
   * anywhere along their length by specifying
   * <code>srcOffset</code> and <code>destOffset</code>.
   * This method does not check to make sure your arrays
   * are large enough to accomodate <code>srcOffset</code> + 3 for
   * the <code>source</code> array or <code>destOffset</code> + 4 for
   * the <code>destination</code> array.
   * The actual number of significant bytes in your array is
   * given by <code>numSigBytes</code>.</p>
   * <p>This is the lowest level of the encoding methods with
   * all possible parameters.</p>
   *
   * @param source the array to convert
   * @param srcOffset the index where conversion begins
   * @param numSigBytes the number of significant bytes in your array
   * @param destination the array to hold the conversion
   * @param destOffset the index where output will be put
   * @return the <code>destination</code> array
   * @since 1.3
   */
  private static byte[] encode3to4(
      final byte[] source, final int srcOffset, final int numSigBytes,
      final byte[] destination, final int destOffset, final int options) {

    final byte[] alphabet = getAlphabet(options);

    //           1         2         3
    // 01234567890123456789012345678901 Bit position
    // --------000000001111111122222222 Array position from threeBytes
    // --------|    ||    ||    ||    | Six bit groups to index ALPHABET
    //          >>18  >>12  >> 6  >> 0  Right shift necessary
    //                0x3f  0x3f  0x3f  Additional AND

    // Create buffer with zero-padding if there are only one or two
    // significant bytes passed in the array.
    // We have to shift left 24 in order to flush out the 1's that appear
    // when Java treats a value as negative that is cast from a byte to an int.
    final int c24 = 24, c8 = 8, c16 = 16, c18 = 18, c12 = 12, c6 = 6;
    final int inBuff = (numSigBytes > 0 ? ((source[srcOffset]       << c24) >>>  c8) : 0)
                     | (numSigBytes > 1 ? ((source[srcOffset + 1] << c24) >>> c16) : 0)
                     | (numSigBytes > 2 ? ((source[srcOffset + 2] << c24) >>> c24) : 0);

    final int mask = 0x3f;
    switch (numSigBytes) {
    case 3:
      destination[destOffset    ] = alphabet[(inBuff >>> c18)      ];
      destination[destOffset + 1] = alphabet[(inBuff >>> c12) & mask];
      destination[destOffset + 2] = alphabet[(inBuff >>>  c6) & mask];
      destination[destOffset + 3] = alphabet[(inBuff)         & mask];
      return destination;

    case 2:
      destination[destOffset    ] = alphabet[(inBuff >>> c18)      ];
      destination[destOffset + 1] = alphabet[(inBuff >>> c12) & mask];
      destination[destOffset + 2] = alphabet[(inBuff >>>  c6) & mask];
      destination[destOffset + 3] = EQUALS_SIGN;
      return destination;

    case 1:
      destination[destOffset    ] = alphabet[(inBuff >>> c18)      ];
      destination[destOffset + 1] = alphabet[(inBuff >>> c12) & mask];
      destination[destOffset + 2] = EQUALS_SIGN;
      destination[destOffset + 3] = EQUALS_SIGN;
      return destination;

    default:
      return destination;
    }   // end switch
  }   // end encode3to4



  /**
   * Performs Base64 encoding on the <code>raw</code> ByteBuffer,
   * writing it to the <code>encoded</code> ByteBuffer.
   * This is an experimental feature. Currently it does not
   * pass along any options (such as {@link #DO_BREAK_LINES}
   * or {@link #GZIP}.
   *
   * @param raw input buffer
   * @param encoded output buffer
   * @since 2.3
   */
  public static void encode(final java.nio.ByteBuffer raw, final java.nio.ByteBuffer encoded) {
    final int c4 = 4;
    final byte[] raw3 = new byte[3];
    final byte[] enc4 = new byte[c4];

    while (raw.hasRemaining()) {
      final int rem = Math.min(3, raw.remaining());
      raw.get(raw3, 0, rem);
      Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
      encoded.put(enc4);
    }   // end input remaining
  }


  /**
   * Performs Base64 encoding on the <code>raw</code> ByteBuffer,
   * writing it to the <code>encoded</code> CharBuffer.
   * This is an experimental feature. Currently it does not
   * pass along any options (such as {@link #DO_BREAK_LINES}
   * or {@link #GZIP}.
   *
   * @param raw input buffer
   * @param encoded output buffer
   * @since 2.3
   */
  public static void encode(final java.nio.ByteBuffer raw, final java.nio.CharBuffer encoded) {
    final int c4 = 4;
    final byte[] raw3 = new byte[3];
    final byte[] enc4 = new byte[c4];

    final int mask = 0xFF;
    while (raw.hasRemaining()) {
      final int rem = Math.min(3, raw.remaining());
      raw.get(raw3, 0, rem);
      Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
      for (int i = 0; i < c4; i++) {
        encoded.put((char)(enc4[i] & mask));
      }
    }   // end input remaining
  }




  /**
   * Serializes an object and returns the Base64-encoded
   * version of that serialized object.
   *
   * <p>As of v 2.3, if the object
   * cannot be serialized or there is another error,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned a null value, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   * The object is not GZip-compressed before being encoded.
   *
   * @param serializableObject The object to encode
   * @return The Base64-encoded object
   * @throws IOException if there is an error
   * @throws NullPointerException if serializedObject is null
   * @since 1.4
   */
  public static String encodeObject(final Serializable serializableObject) throws IOException {
    return encodeObject(serializableObject, NO_OPTIONS);
  }   // end encodeObject


  /**
   * Serializes an object and returns the Base64-encoded
   * version of that serialized object.
   *
   * <p>As of v 2.3, if the object
   * cannot be serialized or there is another error,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned a null value, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   * The object is not GZip-compressed before being encoded.
   * <p>
   * Example options:<pre>
   *   GZIP: gzip-compresses object before encoding it.
   *   DO_BREAK_LINES: break lines at 76 characters
   * </pre>
   * <p>
   * Example: <code>encodeObject(myObj, Base64.GZIP)</code> or
   * <p>
   * Example: <code>encodeObject(myObj, Base64.GZIP | Base64.DO_BREAK_LINES)</code>
   *
   * @param serializableObject The object to encode
   * @param options Specified options
   * @return The Base64-encoded object
   * @see Base64#GZIP
   * @see Base64#DO_BREAK_LINES
   * @throws IOException if there is an error
   * @since 2.0
   */
  public static String encodeObject(final Serializable serializableObject, final int options)
  throws IOException {

    if (serializableObject == null) {
      throw new NullPointerException("Cannot serialize a null object.");
    }   // end if: null

    // Streams
    ByteArrayOutputStream  baos  = null;
    OutputStream           b64os = null;
    java.util.zip.GZIPOutputStream gzos  = null;
    ObjectOutputStream     oos   = null;


    try {
      // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
      baos  = new ByteArrayOutputStream();
      b64os = new Base64.OutputStream(baos, ENCODE | options);
      if ((options & GZIP) != 0) {
        // Gzip
        gzos = new GZIPOutputStream(b64os);
        oos = new ObjectOutputStream(gzos);
      } else {
        // Not gzipped
        oos = new ObjectOutputStream(b64os);
      }
      oos.writeObject(serializableObject);
    } catch (final IOException e) {
      // Catch it and then throw it immediately so that
      // the finally { ignore(); } block is called for cleanup.
      throw e;
    } finally {
      IoUtils.closeQuietly(oos);
      IoUtils.closeQuietly(gzos);
      IoUtils.closeQuietly(b64os);
      IoUtils.closeQuietly(baos);
    }   // end finally

    // Return value according to relevant encoding.
    try {
      return new String(baos.toByteArray(), PREFERRED_ENCODING);
    } catch (final UnsupportedEncodingException uue) {
      // Fall back to some Java default
      return new String(baos.toByteArray());
    }   // end catch

  }   // end encode



  /**
   * Encodes a byte array into Base64 notation.
   * Does not GZip-compress data.
   *
   * @param source The data to convert
   * @return The data in Base64-encoded form
   * @throws NullPointerException if source array is null
   * @since 1.4
   */
  public static String encodeBytes(final byte[] source) {
    // Since we're not going to have the GZIP encoding turned on,
    // we're not going to have an IOException thrown, so
    // we should not force the user to have to catch it.
    String encoded = null;
    try {
      encoded = encodeBytes(source, 0, source.length, NO_OPTIONS);
    } catch (final IOException ex) {
      assert false : ex.getMessage();
    }   // end catch
    assert encoded != null;
    return encoded;
  }   // end encodeBytes



  /**
   * Encodes a byte array into Base64 notation.
   * <p>
   * Example options:<pre>
   *   GZIP: gzip-compresses object before encoding it.
   *   DO_BREAK_LINES: break lines at 76 characters
   *     <i>Note: Technically, this makes your encoding non-compliant.</i>
   * </pre>
   * <p>
   * Example: <code>encodeBytes(myData, Base64.GZIP)</code> or
   * <p>
   * Example: <code>encodeBytes(myData, Base64.GZIP | Base64.DO_BREAK_LINES)</code>
   *
   *
   * <p>As of v 2.3, if there is an error with the GZIP stream,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned a null value, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   *
   * @param source The data to convert
   * @param options Specified options
   * @return The Base64-encoded data as a String
   * @see Base64#GZIP
   * @see Base64#DO_BREAK_LINES
   * @throws IOException if there is an error
   * @throws NullPointerException if source array is null
   * @since 2.0
   */
  public static String encodeBytes(final byte[] source, final int options) throws IOException {
    return encodeBytes(source, 0, source.length, options);
  }   // end encodeBytes


  /**
   * Encodes a byte array into Base64 notation.
   * Does not GZip-compress data.
   *
   * <p>As of v 2.3, if there is an error,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned a null value, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   *
   * @param source The data to convert
   * @param off Offset in array where conversion should begin
   * @param len Length of data to convert
   * @return The Base64-encoded data as a String
   * @throws NullPointerException if source array is null
   * @throws IllegalArgumentException if source array, offset, or length are invalid
   * @since 1.4
   */
  public static String encodeBytes(final byte[] source, final int off, final int len) {
    // Since we're not going to have the GZIP encoding turned on,
    // we're not going to have an IOException thrown, so
    // we should not force the user to have to catch it.
    String encoded = null;
    try {
      encoded = encodeBytes(source, off, len, NO_OPTIONS);
    } catch (final IOException ex) {
      assert false : ex.getMessage();
    }   // end catch
    assert encoded != null;
    return encoded;
  }   // end encodeBytes



  /**
   * Encodes a byte array into Base64 notation.
   * <p>
   * Example options:<pre>
   *   GZIP: gzip-compresses object before encoding it.
   *   DO_BREAK_LINES: break lines at 76 characters
   *     <i>Note: Technically, this makes your encoding non-compliant.</i>
   * </pre>
   * <p>
   * Example: <code>encodeBytes(myData, Base64.GZIP)</code> or
   * <p>
   * Example: <code>encodeBytes(myData, Base64.GZIP | Base64.DO_BREAK_LINES)</code>
   *
   *
   * <p>As of v 2.3, if there is an error with the GZIP stream,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned a null value, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   *
   * @param source The data to convert
   * @param off Offset in array where conversion should begin
   * @param len Length of data to convert
   * @param options Specified options
   * @return The Base64-encoded data as a String
   * @see Base64#GZIP
   * @see Base64#DO_BREAK_LINES
   * @throws IOException if there is an error
   * @throws NullPointerException if source array is null
   * @throws IllegalArgumentException if source array, offset, or length are invalid
   * @since 2.0
   */
  public static String encodeBytes(final byte[] source, final int off, final int len, final int options) throws IOException {
    final byte[] encoded = encodeBytesToBytes(source, off, len, options);

    // Return value according to relevant encoding.
    try {
      return new String(encoded, PREFERRED_ENCODING);
    } catch (final UnsupportedEncodingException uue) {
      return new String(encoded);
    }   // end catch

  }   // end encodeBytes




  /**
   * Similar to {@link #encodeBytes(byte[])} but returns
   * a byte array instead of instantiating a String. This is more efficient
   * if you're working with I/O streams and have large data sets to encode.
   *
   *
   * @param source The data to convert
   * @return The Base64-encoded data as a byte[] (of ASCII characters)
   * @throws NullPointerException if source array is null
   * @since 2.3.1
   */
  public static byte[] encodeBytesToBytes(final byte[] source) {
    byte[] encoded = null;
    try {
      encoded = encodeBytesToBytes(source, 0, source.length, Base64.NO_OPTIONS);
    } catch (final IOException ex) {
      assert false : "IOExceptions only come from GZipping, which is turned off: " + ex.getMessage();
    }
    return encoded;
  }


  /**
   * Similar to {@link #encodeBytes(byte[], int, int, int)} but returns
   * a byte array instead of instantiating a String. This is more efficient
   * if you're working with I/O streams and have large data sets to encode.
   *
   *
   * @param source The data to convert
   * @param off Offset in array where conversion should begin
   * @param len Length of data to convert
   * @param options Specified options
   * @return The Base64-encoded data as a String
   * @see Base64#GZIP
   * @see Base64#DO_BREAK_LINES
   * @throws IOException if there is an error
   * @throws NullPointerException if source array is null
   * @throws IllegalArgumentException if source array, offset, or length are invalid
   * @since 2.3.1
   */
  public static byte[] encodeBytesToBytes(final byte[] source, final int off, final int len, final int options) throws IOException {

    if (source == null) {
      throw new NullPointerException("Cannot serialize a null array.");
    }   // end if: null

    if (off < 0) {
      throw new IllegalArgumentException("Cannot have negative offset: " + off);
    }   // end if: off < 0

    if (len < 0) {
      throw new IllegalArgumentException("Cannot have length offset: " + len);
    }   // end if: len < 0

    if (off + len > source.length) {
      throw new IllegalArgumentException(
          String.format("Cannot have offset of %d and length of %d with array of length %d", off, len, source.length));
    }   // end if: off < 0



    // Compress?
    if ((options & GZIP) != 0) {
      ByteArrayOutputStream  baos  = null;
      java.util.zip.GZIPOutputStream gzos  = null;
      Base64.OutputStream            b64os = null;

      try {
        // GZip -> Base64 -> ByteArray
        baos = new ByteArrayOutputStream();
        b64os = new Base64.OutputStream(baos, ENCODE | options);
        gzos  = new GZIPOutputStream(b64os);

        gzos.write(source, off, len);
        gzos.close();
      } catch (final IOException e) {
        // Catch it and then throw it immediately so that
        // the finally { ignore(); } block is called for cleanup.
        throw e;
      } finally {
        IoUtils.closeQuietly(gzos);
        IoUtils.closeQuietly(b64os);
        IoUtils.closeQuietly(baos);
      }   // end finally

      return baos.toByteArray();
    } else { // Else, don't compress. Better not to use streams at all then.
      final boolean breakLines = (options & DO_BREAK_LINES) != 0;

      //int    len43   = len * 4 / 3;
      //byte[] outBuff = new byte[  (len43)                      // Main 4:3
      //                           + ((len % 3) > 0 ? 4 : 0)      // Account for padding
      //                           + (breakLines ? (len43 / MAX_LINE_LENGTH) : 0)]; // New lines
      // Try to determine more precisely how big the array needs to be.
      // If we get it right, we don't have to do an array copy, and
      // we save a bunch of memory.
      final int c4 = 4;
      int encLen = (len / 3) * c4 + (len % 3 > 0 ? c4 : 0); // Bytes needed for actual encoding
      if (breakLines) {
        encLen += encLen / MAX_LINE_LENGTH; // Plus extra newline characters
      }
      final byte[] outBuff = new byte[encLen];


      int d = 0;
      int e = 0;
      final int len2 = len - 2;
      int lineLength = 0;
      for (; d < len2; d += 3, e += c4) {
        encode3to4(source, d + off, 3, outBuff, e, options);

        lineLength += c4;
        if (breakLines && lineLength >= MAX_LINE_LENGTH) {
          outBuff[e + c4] = NEW_LINE;
          e++;
          lineLength = 0;
        }   // end if: end of line
      }   // en dfor: each piece of array

      if (d < len) {
        encode3to4(source, d + off, len - d, outBuff, e, options);
        e += c4;
      }   // end if: some padding needed


      // Only resize array if we didn't guess it right.
      if (e <= outBuff.length - 1) {
        // If breaking lines and the last byte falls right at
        // the line length (76 bytes per line), there will be
        // one extra byte, and the array will need to be resized.
        // Not too bad of an estimate on array size, I'd say.
        final byte[] finalOut = new byte[e];
        System.arraycopy(outBuff, 0, finalOut, 0, e);
        //System.err.println("Having to resize array from " + outBuff.length + " to " + e);
        return finalOut;
      } else {
        //System.err.println("No need to resize array.");
        return outBuff;
      }

    }   // end else: don't compress

  }   // end encodeBytesToBytes





  /* ********  D E C O D I N G   M E T H O D S  ******** */


  /**
   * Decodes four bytes from array <code>source</code>
   * and writes the resulting bytes (up to three of them)
   * to <code>destination</code>.
   * The source and destination arrays can be manipulated
   * anywhere along their length by specifying
   * <code>srcOffset</code> and <code>destOffset</code>.
   * This method does not check to make sure your arrays
   * are large enough to accomodate <code>srcOffset</code> + 4 for
   * the <code>source</code> array or <code>destOffset</code> + 3 for
   * the <code>destination</code> array.
   * This method returns the actual number of bytes that
   * were converted from the Base64 encoding.
   * <p>This is the lowest level of the decoding methods with
   * all possible parameters.</p>
   *
   *
   * @param source the array to convert
   * @param srcOffset the index where conversion begins
   * @param destination the array to hold the conversion
   * @param destOffset the index where output will be put
   * @param options alphabet type is pulled from this (standard, url-safe, ordered)
   * @return the number of decoded bytes converted
   * @throws NullPointerException if source or destination arrays are null
   * @throws IllegalArgumentException if srcOffset or destOffset are invalid
   *         or there is not enough room in the array.
   * @since 1.3
   */
  private static int decode4to3(
      final byte[] source, final int srcOffset,
      final byte[] destination, final int destOffset, final int options) {

    // Lots of error checking and exception throwing
    if (source == null) {
      throw new NullPointerException("Source array was null.");
    }   // end if
    if (destination == null) {
      throw new NullPointerException("Destination array was null.");
    }   // end if
    if (srcOffset < 0 || srcOffset + 3 >= source.length) {
      throw new IllegalArgumentException(String.format(
          "Source array with length %d cannot have offset of %d and still process four bytes.", source.length, srcOffset));
    }   // end if
    if (destOffset < 0 || destOffset + 2 >= destination.length) {
      throw new IllegalArgumentException(String.format(
          "Destination array with length %d cannot have offset of %d and still store three bytes.", destination.length, destOffset));
    }   // end if


    final byte[] decodabet = getDecodabet(options);

    final int c18 = 18, c12 = 12, c16 = 16, c6 = 6, c8 = 8;

    // Example: Dk==
    if (source[srcOffset + 2] == EQUALS_SIGN) {
      // Two ways to do the same thing. Don't know which way I like best.
      //int outBuff =   ((DECODABET[source[srcOffset   ]] << 24) >>>  6)
      //              | ((DECODABET[source[srcOffset + 1]] << 24) >>> 12);
      final int outBuff = ((decodabet[source[srcOffset    ]] & MASK_0XFF) << c18)
                        | ((decodabet[source[srcOffset + 1]] & MASK_0XFF) << c12);

      destination[destOffset] = (byte)(outBuff >>> c16);
      return 1;
    } else if (source[srcOffset + 3] == EQUALS_SIGN) { // Example: DkL=
      // Two ways to do the same thing. Don't know which way I like best.
      //int outBuff =   ((DECODABET[source[srcOffset    ]] << 24) >>>  6)
      //              | ((DECODABET[source[srcOffset + 1]] << 24) >>> 12)
      //              | ((DECODABET[source[srcOffset + 2]] << 24) >>> 18);
      final int outBuff = ((decodabet[source[srcOffset    ]] & MASK_0XFF) << c18)
                        | ((decodabet[source[srcOffset + 1]] & MASK_0XFF) << c12)
                        | ((decodabet[source[srcOffset + 2]] & MASK_0XFF) << c6);

      destination[destOffset    ] = (byte)(outBuff >>> c16);
      destination[destOffset + 1] = (byte)(outBuff >>> c8);
      return 2;
    } else { // Example: DkLE
      // Two ways to do the same thing. Don't know which way I like best.
      //int outBuff =   ((DECODABET[source[srcOffset    ]] << 24) >>>  6)
      //              | ((DECODABET[source[srcOffset + 1]] << 24) >>> 12)
      //              | ((DECODABET[source[srcOffset + 2]] << 24) >>> 18)
      //              | ((DECODABET[source[srcOffset + 3]] << 24) >>> 24);
      final int outBuff = ((decodabet[source[srcOffset    ]] & MASK_0XFF) << c18)
                        | ((decodabet[source[srcOffset + 1]] & MASK_0XFF) << c12)
                        | ((decodabet[source[srcOffset + 2]] & MASK_0XFF) << c6)
                        | ((decodabet[source[srcOffset + 3]] & MASK_0XFF));


      destination[destOffset    ] = (byte)(outBuff >> c16);
      destination[destOffset + 1] = (byte)(outBuff >> c8);
      destination[destOffset + 2] = (byte)(outBuff);

      return 3;
    }
  }   // end decodeToBytes





  /**
   * Low-level access to decoding ASCII characters in
   * the form of a byte array. <strong>Ignores GUNZIP option, if
   * it's set.</strong> This is not generally a recommended method,
   * although it is used internally as part of the decoding process.
   * Special case: if len = 0, an empty array is returned. Still,
   * if you need more speed and reduced memory footprint (and aren't
   * gzipping), consider this method.
   *
   * @param source The Base64 encoded data
   * @return decoded data
   * @since 2.3.1
   */
  public static byte[] decode(final byte[] source)
  throws IOException {
    byte[] decoded = null;
    //        try {
    decoded = decode(source, 0, source.length, Base64.NO_OPTIONS);
    //        } catch (IOException ex) {
    //            assert false : "IOExceptions only come from GZipping, which is turned off: " + ex.getMessage();
    //        }
    return decoded;
  }



  /**
   * Low-level access to decoding ASCII characters in
   * the form of a byte array. <strong>Ignores GUNZIP option, if
   * it's set.</strong> This is not generally a recommended method,
   * although it is used internally as part of the decoding process.
   * Special case: if len = 0, an empty array is returned. Still,
   * if you need more speed and reduced memory footprint (and aren't
   * gzipping), consider this method.
   *
   * @param source The Base64 encoded data
   * @param off    The offset of where to begin decoding
   * @param len    The length of characters to decode
   * @param options Can specify options such as alphabet type to use
   * @return decoded data
   * @throws IOException If bogus characters exist in source data
   * @since 1.3
   */
  public static byte[] decode(final byte[] source, final int off, final int len, final int options)
      throws IOException {
    final int c4 = 4;

    // Lots of error checking and exception throwing
    if (source == null) {
      throw new NullPointerException("Cannot decode null source array.");
    }   // end if
    if (off < 0 || off + len > source.length) {
      throw new IllegalArgumentException(String.format(
          "Source array with length %d cannot have offset of %d and process %d bytes.", source.length, off, len));
    }   // end if

    if (len == 0) {
      return new byte[0];
    } else if (len < c4) {
      throw new IllegalArgumentException(
          "Base64-encoded string must have at least four characters, but length specified was " + len);
    }   // end if

    final byte[] decodabet = getDecodabet(options);

    final int len34   = len * 3 / c4;       // Estimate on array size
    final byte[] outBuff = new byte[len34]; // Upper limit on size of output
    int    outBuffPosn = 0;             // Keep track of where we're writing

    final byte[] b4        = new byte[c4];     // Four byte buffer from source, eliminating white space
    int    b4Posn    = 0;               // Keep track of four byte input buffer
    int    i         = 0;               // Source array counter
    byte   sbiDecode = 0;               // Special value from DECODABET

    for (i = off; i < off + len; i++) {  // Loop through source

      sbiDecode = decodabet[source[i] & MASK_0XFF];

      // White space, Equals sign, or legit Base64 character
      // Note the values such as -5 and -9 in the
      // DECODABETs at the top of the file.
      if (sbiDecode >= WHITE_SPACE_ENC)  {
        if (sbiDecode >= EQUALS_SIGN_ENC) {
          b4[b4Posn++] = source[i];         // Save non-whitespace
          if (b4Posn > 3) {                  // Time to decode?
            outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn, options);
            b4Posn = 0;

            // If that was the equals sign, break out of 'for' loop
            if (source[i] == EQUALS_SIGN) {
              break;
            }   // end if: equals sign
          }   // end if: quartet built
        }   // end if: equals sign or better
      } else { // end if: white space, equals sign or better
        // There's a bad input character in the Base64 stream.
        throw new IOException(String.format(
            "Bad Base64 input character decimal %d in array position %d", (source[i]) & MASK_0XFF, i));
      }   // end else:
    }   // each input character

    final byte[] out = new byte[outBuffPosn];
    System.arraycopy(outBuff, 0, out, 0, outBuffPosn);
    return out;
  }   // end decode




  /**
   * Decodes data from Base64 notation, automatically
   * detecting gzip-compressed data and decompressing it.
   *
   * @param s the string to decode
   * @return the decoded data
   * @throws IOException If there is a problem
   * @since 1.4
   */
  public static byte[] decode(final String s) throws IOException {
    return decode(s, NO_OPTIONS);
  }



  /**
   * Decodes data from Base64 notation, automatically
   * detecting gzip-compressed data and decompressing it.
   *
   * @param s the string to decode
   * @param options encode options such as URL_SAFE
   * @return the decoded data
   * @throws IOException if there is an error
   * @throws NullPointerException if <tt>s</tt> is null
   * @since 1.4
   */
  public static byte[] decode(final String s, final int options) throws IOException {

    if (s == null) {
      throw new NullPointerException("Input string was null.");
    }   // end if

    byte[] bytes;
    try {
      bytes = s.getBytes(PREFERRED_ENCODING);
    } catch (final UnsupportedEncodingException uee) {
      bytes = s.getBytes();
    }   // end catch
    //</change>

    // Decode
    bytes = decode(bytes, 0, bytes.length, options);

    final int c4 = 4, c8 = 8;

    // Check to see if it's gzip-compressed
    // GZIP Magic Two-Byte Number: 0x8b1f (35615)
    final boolean dontGunzip = (options & DONT_GUNZIP) != 0;
    if ((bytes != null) && (bytes.length >= c4) && (!dontGunzip)) {

      final int head = (bytes[0] & MASK_0XFF) | ((bytes[1] << c8) & MASK_0XFF00);
      if (java.util.zip.GZIPInputStream.GZIP_MAGIC == head)  {
        ByteArrayInputStream  bais = null;
        GZIPInputStream gzis = null;
        ByteArrayOutputStream baos = null;
        final int bufSize = 2048;
        final byte[] buffer = new byte[bufSize];
        int length = 0;

        try {
          baos = new ByteArrayOutputStream();
          bais = new ByteArrayInputStream(bytes);
          gzis = new GZIPInputStream(bais);

          while ((length = gzis.read(buffer)) >= 0) {
            baos.write(buffer, 0, length);
          }   // end while: reading input

          // No error? Get new bytes.
              bytes = baos.toByteArray();

        } catch (final IOException e) {
          e.printStackTrace();
          // Just return originally-decoded bytes
        } finally {
          IoUtils.closeQuietly(baos);
          IoUtils.closeQuietly(gzis);
          IoUtils.closeQuietly(bais);
        }   // end finally

      }   // end if: gzipped
    }   // end if: bytes.length >= 2

    return bytes;
  }   // end decode



  /**
   * Attempts to decode Base64 data and deserialize a Java
   * Object within. Returns <tt>null</tt> if there was an error.
   *
   * @param encodedObject The Base64 data to decode
   * @return The decoded and deserialized object
   * @throws NullPointerException if encodedObject is null
   * @throws IOException if there is a general error
   * @throws ClassNotFoundException if the decoded object is of a
   *         class that cannot be found by the JVM
   * @since 1.5
   */
  public static Object decodeToObject(final String encodedObject)
  throws IOException, java.lang.ClassNotFoundException {
    return decodeToObject(encodedObject, NO_OPTIONS, null);
  }


  /**
   * Attempts to decode Base64 data and deserialize a Java
   * Object within. Returns <tt>null</tt> if there was an error.
   * If <tt>loader</tt> is not null, it will be the class loader
   * used when deserializing.
   *
   * @param encodedObject The Base64 data to decode
   * @param options Various parameters related to decoding
   * @param loader Optional class loader to use in deserializing classes.
   * @return The decoded and deserialized object
   * @throws NullPointerException if encodedObject is null
   * @throws IOException if there is a general error
   * @throws ClassNotFoundException if the decoded object is of a
   *         class that cannot be found by the JVM
   * @since 2.3.4
   */
  public static Object decodeToObject(
      final String encodedObject, final int options, final ClassLoader loader)
  throws IOException, java.lang.ClassNotFoundException {

    // Decode and gunzip if necessary
    final byte[] objBytes = decode(encodedObject, options);

    ByteArrayInputStream  bais = null;
    ObjectInputStream     ois  = null;
    Object obj = null;

    try {
      bais = new ByteArrayInputStream(objBytes);

      // If no custom class loader is provided, use Java's builtin OIS.
      if (loader == null) {
        ois  = new ObjectInputStream(bais);
      } else { // end if: no loader provided
        // Else make a customized object input stream that uses
        // the provided class loader.
        ois = new ObjectInputStream(bais) {
          @Override
          public Class<?> resolveClass(final ObjectStreamClass streamClass) throws IOException, ClassNotFoundException {
            final Class<?> c = Class.forName(streamClass.getName(), false, loader);
            if (c == null) {
              return super.resolveClass(streamClass);
            } else {
              return c;   // Class loader knows of this class.
            }   // end else: not null
          }   // end resolveClass
        };  // end ois
      }   // end else: no custom class loader

      obj = ois.readObject();
    } catch (final IOException e) {
      throw e;    // Catch and throw in order to execute finally { ignore(); }
    } catch (final java.lang.ClassNotFoundException e) {
      throw e;    // Catch and throw in order to execute finally { ignore(); }
    } finally {
      IoUtils.closeQuietly(bais);
      IoUtils.closeQuietly(ois);
    }   // end finally

    return obj;
  }   // end decodeObject



  /**
   * Convenience method for encoding data to a file.
   *
   * <p>As of v 2.3, if there is a error,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned false, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   * @param dataToEncode byte array of data to encode in base64 form
   * @param filename Filename for saving encoded data
   * @throws IOException if there is an error
   * @throws NullPointerException if dataToEncode is null
   * @since 2.1
   */
  public static void encodeToFile(final byte[] dataToEncode, final String filename)
  throws IOException {

    if (dataToEncode == null) {
      throw new NullPointerException("Data to encode was null.");
    }   // end iff

    Base64.OutputStream bos = null;
    try {
      bos = new Base64.OutputStream(
          new FileOutputStream(filename), Base64.ENCODE);
      bos.write(dataToEncode);
    } catch (final IOException e) {
      throw e; // Catch and throw to execute finally { ignore(); } block
    } finally {
      IoUtils.closeQuietly(bos);
    }   // end finally

  }   // end encodeToFile


  /**
   * Convenience method for decoding data to a file.
   *
   * <p>As of v 2.3, if there is a error,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned false, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   * @param dataToDecode Base64-encoded data as a string
   * @param filename Filename for saving decoded data
   * @throws IOException if there is an error
   * @since 2.1
   */
  public static void decodeToFile(final String dataToDecode, final String filename)
  throws IOException {

    Base64.OutputStream bos = null;
    try {
      bos = new Base64.OutputStream(
          new FileOutputStream(filename), Base64.DECODE);
      bos.write(dataToDecode.getBytes(PREFERRED_ENCODING));
    } catch (final IOException e) {
      throw e; // Catch and throw to execute finally { ignore(); } block
    } finally {
      IoUtils.closeQuietly(bos);
    }   // end finally

  }   // end decodeToFile




  /**
   * Convenience method for reading a base64-encoded
   * file and decoding it.
   *
   * <p>As of v 2.3, if there is a error,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned false, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   * @param filename Filename for reading encoded data
   * @return decoded byte array
   * @throws IOException if there is an error
   * @since 2.1
   */
  public static byte[] decodeFromFile(final String filename)
  throws IOException {

    byte[] decodedData = null;
    Base64.InputStream bis = null;
    try {
      // Set up some useful variables
      final File file = new File(filename);
      byte[] buffer = null;
      int length   = 0;
      int numBytes = 0;

      // Check for size of file
      if (file.length() > Integer.MAX_VALUE) {
        throw new IOException("File is too big for this convenience method (" + file.length() + " bytes).");
      }   // end if: file too big for int index
      buffer = new byte[(int)file.length()];

      // Open a stream
      bis = new Base64.InputStream(
          new BufferedInputStream(
              new FileInputStream(file)), Base64.DECODE);

      final int maxCount = 4096;
      // Read until done
      while ((numBytes = bis.read(buffer, length, maxCount)) >= 0) {
        length += numBytes;
      }   // end while

      // Save in a variable to return
      decodedData = new byte[length];
      System.arraycopy(buffer, 0, decodedData, 0, length);

    } catch (final IOException e) {
      throw e; // Catch and release to execute finally { ignore(); }
    } finally {
      IoUtils.closeQuietly(bis);
    }   // end finally

    return decodedData;
  }   // end decodeFromFile



  /**
   * Convenience method for reading a binary file
   * and base64-encoding it.
   *
   * <p>As of v 2.3, if there is a error,
   * the method will throw an IOException. <b>This is new to v2.3!</b>
   * In earlier versions, it just returned false, but
   * in retrospect that's a pretty poor way to handle it.</p>
   *
   * @param filename Filename for reading binary data
   * @return base64-encoded string
   * @throws IOException if there is an error
   * @since 2.1
   */
  public static String encodeFromFile(final String filename)
  throws IOException {

    String encodedData = null;
    Base64.InputStream bis = null;
    try {
      // Set up some useful variables
      final File file = new File(filename);
      final double factor = 1.4;
      final int maxBuffer = 40;
      final byte[] buffer = new byte[Math.max((int)(file.length() * factor + 1), maxBuffer)]; // Need max() for math on small files (v2.2.1); Need +1 for a few corner cases (v2.3.5)
      int length   = 0;
      int numBytes = 0;

      // Open a stream
      bis = new Base64.InputStream(
          new BufferedInputStream(
              new FileInputStream(file)), Base64.ENCODE);

      // Read until done
      final int maxCount = 4096;
      while ((numBytes = bis.read(buffer, length, maxCount)) >= 0) {
        length += numBytes;
      }   // end while

      // Save in a variable to return
      encodedData = new String(buffer, 0, length, Base64.PREFERRED_ENCODING);

    } catch (final IOException e) {
      throw e; // Catch and release to execute finally { ignore(); }
    } finally {
      IoUtils.closeQuietly(bis);
    }   // end finally

    return encodedData;
  }   // end encodeFromFile

  /**
   * Reads <tt>infile</tt> and encodes it to <tt>outfile</tt>.
   *
   * @param infile Input file
   * @param outfile Output file
   * @throws IOException if there is an error
   * @since 2.2
   */
  public static void encodeFileToFile(final String infile, final String outfile)
  throws IOException {

    final String encoded = Base64.encodeFromFile(infile);
    java.io.OutputStream out = null;
    try {
      out = new BufferedOutputStream(
          new FileOutputStream(outfile));
      out.write(encoded.getBytes("US-ASCII")); // Strict, 7-bit output.
    } catch (final IOException e) {
      throw e; // Catch and release to execute finally { ignore(); }
    } finally {
      IoUtils.closeQuietly(out);
    }   // end finally
  }   // end encodeFileToFile


  /**
   * Reads <tt>infile</tt> and decodes it to <tt>outfile</tt>.
   *
   * @param infile Input file
   * @param outfile Output file
   * @throws IOException if there is an error
   * @since 2.2
   */
  public static void decodeFileToFile(final String infile, final String outfile)
  throws IOException {

    final byte[] decoded = Base64.decodeFromFile(infile);
    java.io.OutputStream out = null;
    try {
      out = new BufferedOutputStream(
          new FileOutputStream(outfile));
      out.write(decoded);
    } catch (final IOException e) {
      throw e; // Catch and release to execute finally { ignore(); }
    } finally {
      IoUtils.closeQuietly(out);
    }   // end finally
  }   // end decodeFileToFile


  /* ********  I N N E R   C L A S S   I N P U T S T R E A M  ******** */



  /**
   * A {@link Base64.InputStream} will read data from another
   * <tt>InputStream</tt>, given in the constructor,
   * and encode/decode to/from Base64 notation on the fly.
   *
   * @see Base64
   * @since 1.3
   */
  public static class InputStream extends FilterInputStream {

    /** Encoding or decoding. */
    private boolean encode;
    /** Current position in the buffer. */
    private int     position;
    /** Small buffer holding converted data. */
    private byte[]  buffer;
    /** Length of buffer (3 or 4). */
    private int     bufferLength;
    /** Number of meaningful bytes in the buffer. */
    private int     numSigBytes;
    /** Line length. */
    private int     lineLength;
    /** Break lines at less than 80 characters. */
    private boolean breakLines;
    /** Record options used to create the stream. */
    private int     options;
    /** Local copies to avoid extra method calls. */
    private byte[]  decodabet;


    /**
     * Constructs a {@link Base64.InputStream} in DECODE mode.
     *
     * @param in the <tt>InputStream</tt> from which to read data.
     * @since 1.3
     */
    public InputStream(final java.io.InputStream in) {
      this(in, DECODE);
    }   // end constructor


    /**
     * Constructs a {@link Base64.InputStream} in
     * either ENCODE or DECODE mode.
     * <p>
     * Valid options:<pre>
     *   ENCODE or DECODE: Encode or Decode as data is read.
     *   DO_BREAK_LINES: break lines at 76 characters
     *     <i>(only meaningful when encoding)</i>
     * </pre>
     * <p>
     * Example: <code>new Base64.InputStream(in, Base64.DECODE)</code>
     *
     *
     * @param in the <tt>InputStream</tt> from which to read data.
     * @param options Specified options
     * @see Base64#ENCODE
     * @see Base64#DECODE
     * @see Base64#DO_BREAK_LINES
     * @since 2.0
     */
    public InputStream(final java.io.InputStream in, final int options) {

      super(in);
      this.options      = options; // Record for later
      this.breakLines   = (options & DO_BREAK_LINES) > 0;
      this.encode       = (options & ENCODE) > 0;
      final int c4 = 4;
      this.bufferLength = encode ? c4 : 3;
      this.buffer       = new byte[bufferLength];
      this.position     = -1;
      this.lineLength   = 0;
      this.decodabet    = getDecodabet(options);
    }   // end constructor

    /**
     * Reads enough of the input stream to convert
     * to/from Base64 and returns the next byte.
     *
     * @return next byte
     * @since 1.3
     */
    @Override
    public int read() throws IOException  {

      // Do we need to get data?
      if (position < 0) {
        if (encode) {
          final byte[] b3 = new byte[3];
          int numBinaryBytes = 0;
          for (int i = 0; i < 3; i++) {
            final int b = in.read();

            // If end of stream, b is -1.
            if (b >= 0) {
              b3[i] = (byte)b;
              numBinaryBytes++;
            } else {
              break; // out of for loop
            }   // end else: end of stream

          }   // end for: each needed input byte

          if (numBinaryBytes > 0) {
            encode3to4(b3, 0, numBinaryBytes, buffer, 0, options);
            position = 0;
            final int c4 = 4;
            numSigBytes = c4;
          } else {
            return -1;  // Must be end of stream
          }   // end else
        } else {
          // Else decoding
          final int c4 = 4;
          final byte[] b4 = new byte[c4];
          int i = 0;
          for (i = 0; i < c4; i++) {
            // Read four "meaningful" bytes:
            int b = 0;
            final int mask = 0x7f;
            do { b = in.read(); }
            while (b >= 0 && decodabet[b & mask] <= WHITE_SPACE_ENC);

            if (b < 0) {
              break; // Reads a -1 if end of stream
            }   // end if: end of stream

            b4[i] = (byte)b;
          }   // end for: each needed input byte

          if (i == c4) {
            numSigBytes = decode4to3(b4, 0, buffer, 0, options);
            position = 0;
          } else if (i == 0) { // end if: got four characters
            return -1;
          } else { // also padded correctly
            // Must have broken out from above.
            throw new IOException("Improperly padded Base64 input.");
          }   // end

        }   // end else: decode
      }   // end else: get data

      // Got data?
      if (position >= 0) {
        // End of relevant data?
        if (/*!encode &&*/ position >= numSigBytes) {
          return -1;
        }   // end if: got data

        if (encode && breakLines && lineLength >= MAX_LINE_LENGTH) {
          lineLength = 0;
          return '\n';
        } else {
          lineLength++;   // This isn't important when decoding
          // but throwing an extra "if" seems
          // just as wasteful.

          final int b = buffer[position++];

          if (position >= bufferLength) {
            position = -1;
          }   // end if: end

          return b & MASK_0XFF; // This is how you "cast" a byte that's
          // intended to be unsigned.
        }   // end else
      } else {
        throw new IOException("Error in Base64 code reading stream.");
      }   // end else
    }   // end read


    /**
     * Calls {@link #read()} repeatedly until the end of stream
     * is reached or <code>len</code> bytes are read.
     * Returns number of bytes read into array or -1 if
     * end of stream is encountered.
     *
     * @param dest array to hold values
     * @param off offset for array
     * @param len max number of bytes to read into array
     * @return bytes read into array or -1 if end of stream is encountered.
     * @since 1.3
     */
    @Override
    public int read(final byte[] dest, final int off, final int len)
    throws IOException {
      int i;
      int b;
      for (i = 0; i < len; i++) {
        b = read();

        if (b >= 0) {
          dest[off + i] = (byte) b;
        } else if (i == 0) {
          return -1;
        } else {
          break; // Out of 'for' loop
        } // Out of 'for' loop
      }   // end for: each byte read
      return i;
    }   // end read

  }   // end inner class InputStream






  /* ********  I N N E R   C L A S S   O U T P U T S T R E A M  ******** */



  /**
   * A {@link Base64.OutputStream} will write data to another
   * <tt>OutputStream</tt>, given in the constructor,
   * and encode/decode to/from Base64 notation on the fly.
   *
   * @see Base64
   * @since 1.3
   */
  public static class OutputStream extends FilterOutputStream {

    /** Encoding or decoding. */
    private boolean encode;
    /** Current position in the buffer. */
    private int     position;
    /** Small buffer holding converted data. */
    private byte[]  buffer;
    /** Length of buffer (3 or 4). */
    private int     bufferLength;
    /** Line length. */
    private int     lineLength;
    /** Break lines at less than 80 characters. */
    private boolean breakLines;
    /** Record options used to create the stream. */
    private int     options;
    /** Local copies to avoid extra method calls. */
    private byte[]  decodabet;
    /** Scratch used in a few places. */
    private byte[]  b4;
    /** Suspend flag. */
    private boolean suspendEncoding;

    /**
     * Constructs a {@link Base64.OutputStream} in ENCODE mode.
     *
     * @param out the <tt>OutputStream</tt> to which data will be written.
     * @since 1.3
     */
    public OutputStream(final java.io.OutputStream out) {
      this(out, ENCODE);
    }   // end constructor


    /**
     * Constructs a {@link Base64.OutputStream} in
     * either ENCODE or DECODE mode.
     * <p>
     * Valid options:<pre>
     *   ENCODE or DECODE: Encode or Decode as data is read.
     *   DO_BREAK_LINES: don't break lines at 76 characters
     *     <i>(only meaningful when encoding)</i>
     * </pre>
     * <p>
     * Example: <code>new Base64.OutputStream(out, Base64.ENCODE)</code>
     *
     * @param out the <tt>OutputStream</tt> to which data will be written.
     * @param options Specified options.
     * @see Base64#ENCODE
     * @see Base64#DECODE
     * @see Base64#DO_BREAK_LINES
     * @since 1.3
     */
    public OutputStream(final java.io.OutputStream out, final int options) {
      super(out);
      this.breakLines   = (options & DO_BREAK_LINES) != 0;
      this.encode       = (options & ENCODE) != 0;
      final int c4 = 4;
      this.bufferLength = encode ? 3 : c4;
      this.buffer       = new byte[bufferLength];
      this.position     = 0;
      this.lineLength   = 0;
      this.suspendEncoding = false;
      this.b4           = new byte[c4];
      this.options      = options;
      this.decodabet    = getDecodabet(options);
    }   // end constructor


    /**
     * Writes the byte to the output stream after
     * converting to/from Base64 notation.
     * When encoding, bytes are buffered three
     * at a time before the output stream actually
     * gets a write() call.
     * When decoding, bytes are buffered four
     * at a time.
     *
     * @param theByte the byte to write
     * @since 1.3
     */
    @Override
    public void write(final int theByte)
    throws IOException {
      // Encoding suspended?
      if (suspendEncoding) {
        this.out.write(theByte);
        return;
      }   // end if: supsended

      // Encode?
      if (encode) {
        buffer[position++] = (byte)theByte;
        if (position >= bufferLength) { // Enough to encode.

          this.out.write(encode3to4(b4, buffer, bufferLength, options));

          final int c4 = 4;
          lineLength += c4;
          if (breakLines && lineLength >= MAX_LINE_LENGTH) {
            this.out.write(NEW_LINE);
            lineLength = 0;
          }   // end if: end of line

          position = 0;
        }   // end if: enough to output
      } else {
        // Meaningful Base64 character?
        final int mask = 0x7f;
        if (decodabet[theByte & mask] > WHITE_SPACE_ENC) {
          buffer[position++] = (byte)theByte;
          if (position >= bufferLength) { // Enough to output.

            final int len = Base64.decode4to3(buffer, 0, b4, 0, options);
            out.write(b4, 0, len);
            position = 0;
          }   // end if: enough to output
        } else if (decodabet[theByte & mask] != WHITE_SPACE_ENC) {
          throw new IOException("Invalid character in Base64 data.");
        }   // end else: not white space either
      }   // end else: decoding
    }   // end write



    /**
     * Calls {@link #write(int)} repeatedly until <code>len</code>
     * bytes are written.
     *
     * @param theBytes array from which to read bytes
     * @param off offset for array
     * @param len max number of bytes to read into array
     * @since 1.3
     */
    @Override
    public void write(final byte[] theBytes, final int off, final int len)
    throws IOException {
      // Encoding suspended?
      if (suspendEncoding) {
        this.out.write(theBytes, off, len);
        return;
      }   // end if: supsended

      for (int i = 0; i < len; i++) {
        write(theBytes[off + i]);
      }   // end for: each byte written

    }   // end write



    /**
     * Method added by PHIL. [Thanks, PHIL. -Rob]
     * This pads the buffer without closing the stream.
     * @throws IOException  if there's an error.
     */
    public void flushBase64() throws IOException  {
      if (position > 0) {
        if (encode) {
          out.write(encode3to4(b4, buffer, position, options));
          position = 0;
        } else {
          throw new IOException("Base64 input not properly padded.");
        }   // end else: decoding
      }   // end if: buffer partially full

    }   // end flush


    /**
     * Flushes and closes (I think, in the superclass) the stream.
     *
     * @since 1.3
     */
    @Override
    public void close() throws IOException {
      // 1. Ensure that pending characters are written
      flushBase64();

      // 2. Actually close the stream
      // Base class both flushes and closes.
      super.close();

      buffer = null;
      out    = null;
    }   // end close



    /**
     * Suspends encoding of the stream.
     * May be helpful if you need to embed a piece of
     * base64-encoded data in a stream.
     *
     * @throws IOException  if there's an error flushing
     * @since 1.5.1
     */
    public void suspendEncoding() throws IOException  {
      flushBase64();
      this.suspendEncoding = true;
    }   // end suspendEncoding


    /**
     * Resumes encoding of the stream.
     * May be helpful if you need to embed a piece of
     * base64-encoded data in a stream.
     *
     * @since 1.5.1
     */
    public void resumeEncoding() {
      this.suspendEncoding = false;
    }   // end resumeEncoding



  }   // end inner class OutputStream


}   // end class Base64
